| 摘要: |
| 依据中华绒螯蟹正常血糖水平和摄食、饥饿条件下的血糖变动范围[(0.43±0.06)—(0.73±0.08)mmol/L], 选择不同浓度葡萄糖, 采用全细胞膜片钳技术, 在单个细胞水平观察葡萄糖对中华绒螯蟹眼柄分泌CHH细胞高电压激活钙电流(ICa)的调控作用, 探讨眼柄神经内分泌调控的生物物理机制。通过实时监测细胞膜电容的变化, 观察去极化电压诱导的分泌CHH细胞ICa对细胞分泌的影响,发现ICa的大小与细胞的分泌强度呈明显的正相关；灌流正常中华绒螯蟹生理浓度的葡萄糖(0.3、0.9、1mmol/L)对细胞ICa无明显影响, 高浓度葡萄糖(3、10mmol/L)灌流10—20min, 对细胞ICa产生显著的抑制作用, 但对细胞膜通道的激活、失活电压等电生理特征无明显的影响。这表明血糖水平通过抑制细胞ICa对中华绒螯蟹眼柄CHH神经多肽激素分泌活动产生快速的负反馈调节, 以维持中华绒螯蟹的正常生理血糖水平。
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| 关键词: 中华绒螯蟹, 神经内分泌细胞, 葡萄糖, 钙电流, 膜片钳技术 |
| DOI：10.11693/hyhz200906008008 |
| 分类号: |
| 基金项目:国家自然科学基金项目, 30871907 号, 30451421 号 |
附件 |
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| EFFECTS OF GLUCOSE ON ICa DISSOLVED FROM CHH-IMMUNAREACTIVE CELLS IN EYESTALKS OF CRAB ERICHEIR SINENSIS |
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FAN Xiao-Rui, SUN Jin-Sheng
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College of Chemistry and Life Sciences, Tianjin Normal University
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| Abstract: |
| Chinese mitten crabs (Eriocheir sinensis) is one of the important economical valuable crustacean in China. Its X-organ-sinus gland (XO-SG) complex is an important neurosecretory organ analogous to vertebrate hypothalamo-neurohypophyseal system, from which some peptide hormones are produced, including crustacean hyperglycemia hormone (CHH), molt-inhibiting hormone (MIH), gonad-inhibiting hormone (GIH), and so on. These neuropeptides play a key role in regulating various important physiological processes, such as molting, reproduction, carbohydrate metabolism, pigment migration, and osmoregulation. Immunocytochemical localization and immunobloting showed that the anti-CHH immunoreactive cells were located on the proximal surface of X-organ. The secretion activity stimulated by depolarized voltage was real-time monitored using whole cell patch clamp technique, and combined with membrane capacitance measurement in single cell after cell plating. CHH that regulated the metabolism and blood glucose level of organism was synthesized and secreted by type A neuroseretory cells dissociated from the MTXO in the eyestalks. At blood glucose of (0.43±0.06)—(0.73±0.08) mmol/L, the crabs were fed or starved in five concentrations of glucose, during which the effect of blood glucose on the ICa dissolved from the CHH-immunoreactive cells in the eyestalks was observed in whole cell patch clamp technique with real-time monitoring of cell membrane capacitance. The results show that the ICa is positively correlated with the secretion of CHH. In response to rapid application of varies glucose concentrations (0.3, 0.9, 1, 3, and 10mmol/L), ICa was inhibited by higher concentrations above 3mmol/L in 10—20min, and the electrophysiological characteristics of calcium channels, such as activation and inactivation potential, were not obviously altered. Therefore, the blood glucose could play negative feedback at the secretion of CHH to normal level by quickly reducing ICa from type A cells in the MTXO dissociated in the eyestalks.
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| Key words: Eriocheir sinensis, Neurosecretory cell, Glucose, ICa, Patch clamp technique |
